Date: Wednesday, March 9, 2005 Time: 4:00 p.m. Room: Little Hall (LIT) 109 Opening Remarks by Herb Wilf Distinguished Professor University of Pennsylvania Refreshments: 5:00 p.m. in LIT 339

Abstract: I will start with Andrei Markov's 1890 almost-discovery of WZ pairs, continue with Sister Celine's 1945 almost-discovery that hypergeometric (alias binomial cofficients) sums are decidable, then on to Bill Gosper's 1977 missed opportunity to extend his method from indefinite to definite summation, then to Z's 1988 Slow algorithm, then to Z's 1989 fast algorithm, then to W's 1990 great contibutions, followed by the 1992 WZ extension to several variables, then to the 2004 simplifications and sharpening by Z and Mohamud Mohammed, all the way to the year 2100 and beyond.

 ^* New Jersey Board of Regents Professor Doron Zeilberger of Rutgers University is one of the world's most eminent researchers in the area of Discrete Mathematics. He has made outstanding contributions to the theory of hypergeometric and $q$-hypergeometric series, the study of the celebrated Rogers-Ramanujan identities, and the resolution of the famous Alternating Sign Matrix Conjecture. In collaboration with Herb Wilf, Professor Zeilberger discovered the powerful W-Z Algorithm, which supplies proofs of a large class of identities. For this Wilf and Zeilberger were awarded the Leroy P. Steele Prize of the American Mathematical Society.

This History Lecture is one of the featured events of the International Conference on Pattern Avoiding Permutations which is taking place during March 7-11, 2005. See the website:
http://www.math.haifa.ac.il/toufik/conf_2005/pp05.html.